Terminal construction and method of making the same



Dec. 3, 1963 R. G. MAWNEY ETAL ,978

TERMINAL CONSTRUCTION AND METHOD OF MAKING THE SAME Filed July 1, 1960 2 Sheets-Sheet 1 Robert 6. Ma zwzqy,

Att y,

Inventors:

Walter 3. Harper, Jz',

1963 R. e. MAWNEY ETAL 78 TERMINAL CONSTRUCTION AND METHOD OF MAKING THE SAME Filed July 1, 1960 2 Sheets-Sheet 2 gm la u Inventors fioZert 61 Mall/racy,

Waiter 1?. Ear 0; Jr, g4 4 A t 't United States Patent 3,112,978 TERB/ilNAL CGNSTRUQTEGN AND METHGD OF MAKING THE SAME Robert G. Mawney, Attleboro, Mass, and Waiter R.

Harper, Era, Burlington, Rl, assigncrs to Texas instruments incorporated, Dallas, Tern, a corporation of Delaware Filed July 1, 1960, Ser. No. 46,337 19 Claims. (til. 339-217) This invention relates to a new and improved construction, and means for firmly securing an element to a base or housing member, and in particular, relates to a new and improved terminal construction whereby an electrical terminal is firmly fastened to a base or housing member.

It is one object of the invention to provide a novel and improved terminal construction whereby a terminal can be fixedly and firmly attached to another member, such as a base member, in a simple and economical fashion.

it is another object of the invention to provide a terminal construction whereby the terminal can be firmly and securely attached to a base member formed of a frangible or relatively brittle material without incurring cracking or fracture of the base member.

It is another object of the invention to provide an electrical terminal construction which firmly mounts the terminal on a base and which is not subject to loosening from the base upon expansion thereof when subjected to elevated temperatures during operation.

it is a further object of the invention to provide a terminal construction wherein the terminal is fixedly and firmly secured to a base member and will remain tightly secured theretoduring operation at elevated temperatures.

t is a further object of the invention to provide a terminal construction wherein the terminal, after being fixedly and tightly secured to a base member, resiliently maintains its tightness of fit therewith.

It is a further object of the invention to provide a terminal construction which is susceptible to low-cost mass production and is simple and economical to manufacture and assemble.

It is yet a further object of the invention to provide a new and improved method of tightly and fixedly mounting a terminal on a base or housing member.

It is yet a further object of the invention to provide a new and improved method of firmly and tightly mounting electrical terminals on a base member or housing member of frangible or brittle material.

it is a further object of the invention to provide a new and improved method of making a terminal construction whereby terminals of substantial mass and thicknesses can be quickly and easily, firmly secured to a base member in a simple and reliable manner.

Other objects will be in part apparent and in part pointed out hereinafter.

The invention accordingly comprises the elements and combinations of elements, steps and sequence of steps, features of construction and manipulation, and arrangements of parts, all of which will be exemplified in the structures and methods hereinafter described, and the scope of the application of which will be indicated in the following claims.

In the accompanying drawings, in which one of various possible embodiments of the invention are illustrated:

FIG. 1 is a plan view of one embodiment of this invention;

FIG. 2 is a cross sectional view taken on line 2-2 of FIG. 1;

3 ,ll2,9 ?8 Patented Dec. 3, 1963 ice FIG. 3 is a cross sectional view taken on line 3-3 of FIG. 2;

FIG. 3a is a view similar to FIG. 3, but showing the parts in a condition prior to securement in final assembled relation;

PEG. 4 is a view similar to FIG. 1, but omitting certain parts for clarity of illustration;

FIG. 5 is a sectional view taken on line 5-5 of FIG. 6;

FIG. 6 is a sectional view taken on line 66 of FIG. 5;

FIG. 7 is a perspective view illustrating one of the parts according to the instant invention;

FIG. 8 is a front elevational view illustrating another embodiment of one of the parts according to the instant invention; and

FIG. 9 is a side elevational view of the part shown in FIG. 8.

Similar reference characters indicate corresponding parts throughout the several views of the drawings.

In the manufacture of electrical components, such as, for example, electrical switches, use is oftentimes made of electrical terminals or electrical contact structures which are mounted on an insulating terminal block, base member, or some other part of the switch structure.

Due to manufacturing tolerances and commercial expediency, it is relatively expensive to have an aperture (into which a terminal is ordinarily inserted) formed in a base member, into which the terminal is ordinarily inserted, to be the exact size and to exactly complement the size and shape of the terminal, so as to eliminate free play and looseness of fit between the terminal and the base member. There are many types of electrical switches, for example, of the kind shown in the Bolesky Patent No. 2,199,387, where free play or looseness of fit between the terminal and the base member is objectionable. Such looseness of fit of the terminal may result in deleterious shifts or changes in the calibration of the thermostatic element, particularly where the terminal serves as a stationary electrical contact which is engageable with contacts carried by the thermostatic element. It can thus be seen that it is of considerable importance to provide a terminal construction wherein the terminal is mounted to a base member firmly and securely so as to preclude any relative movement therebetween in service or operation.

Heretofore terminals have conventionally been mounted or secured to a base member or switch housing by means of staking or crimping. The conventional staking procedure generally involves a peening or forming operation in which a small section of the metallic terminal is deformed and forced into pressure contact with a mating surface of the base member. Generally, in order to achieve a firm or tightness of fit in the mounting between the terminal and base member, repeated blows or peening is often necessary. Also, in order to achieve a firm or tight fit in the mounting of the terminal on the base member with the staking process, it is generally essential that the backing or base material (which provides a mating surface for the terminal) be resilient, and allow the staked metallic material of the terminal to progressively further deform with each staking blow. The inherent elasticity of the metallic material of the terminal usually resists complete permanent deformation and tends, in part, to return to its shape prior to deformation by the staking blows, which thereby tends to produce a loose fit between the base member and terminal. The tendency to produce a loose fit between the terminal and the base member created by the elasticity or resistance to plastic or permanent deformation by the terminal, is generally minimized by the resilience or inherent elasticity of the base material that is ordinarily employed with the staking operations. Such electrically insulating base materials as as are ordinarily employed with staking operations include phenolic and resinous type organic materials. These materials being inherently resilient or elastic, tend to return to their original shape prior to the staking blows and produce a force against the staked or deformed metallic material of the terminal, and thereby tend to minimize the looseness of fit between the terminal and base member.

The conventional staking methods, however, pose many problems and are not suitable where the base member or materials are formed of electrically insulating materials that are not resilient or which are frangible and brittle. Such refractory or frangible materials as ceramics glass mica type materials, and various types of refractory materials, have become increasingly desirable for use in electrical switches because of both their ability to withstand higher elevated temperature conditions than that of phenolic or other resinous organic materials and their characteristic of being relatively chemically inert, which latter attribute is particularly advantageous in obviating contamination and corrosion problems in hermetically sealed, electrical switch applications.

Further, conventional staking methods are not practical, and in many cases, not possible when terminals of relatively large size or gauge are employed. With terminals of substantial mass, staking requires extremely high peening or forming forces which cause fracturing of even resilient base materials. When conventional staking methods are applied to even thin gauge terminals with frangible base materials, such as those mentioned above, cracking and fracturing of the base material preclude a practical application of this conventional method. By comparison, the instant invention obviates the problems mentioned above and is applicable to securing terminals in varying sizes from relatively thin terminals to terminals of substantial mass to base members which are formed of either resilient or frangible materials.

Referring now to the drawings, and particularly FIG. 1, there is shown a base member to which it is frequently desirable to secure one or more terminals for the purpose of electrically communicating between the interior and exterior of the base member. Base member lit? may, for example, form part of the housing of an electrical switch. Base 14 may be formed of an electrically insulating material, such as often used in electrical switches. Such electrically insulating materials may, for example, be a frangible or brittle material such as one of the refractory materials, e.g. Mycalex (a registered trademark of the Mycalex Corp. of America for a glass bonded insulated material) or a ceramic material, or may be an inherently resilient material such as a phenolic or one of the resinous organic thermosetting materials.

As best seen in FIGS. 4-6, base member MB is provided with an open-ended slot or aperture 12. Base 16 is further provided with a depression or cavity 14 adjacent to and opening into and communicating with longitudinally extending open-ended slot 12. As best seen in FIGS. 5 and 6, cavity or depression 14 includes a retainer well portion 15 as defined by walls 16, i7 and 18, and a pair of sloping shoulder or wedging surfaces 2t? and 22 extending transversely and upwardly away from opposite sides of retainer well 15, as best seen in FIG. 5.

Referring now to FIG. 3a, leg 24 of an L-shaped terminal is slidably inserted into elongated open-ended slot 12. As best shown in FIG. 3a, legs 26 and 24 of the L-shaped terminal are initially formed with an acute angle therebetween, which acute angle will approach a right angle after the terminal has been fixed in final assembled relation, as shown in FIG. 3. As will be more fully described below, the terminal, when fixed in final assembled relation, as shown in FIG. 3, stresses leg 26 (which pivots or bends with respect to leg 24 at the junction thereof), whereupon the terminal acts as a spring member, and upon expansion thereof, at elevated temperatures (which coefiicient of thermal expansion of the terminal member is usually greater than that of the base material), a tight fit will be assured between the terminal and base member irrespective of the relative expansion between the parts.

The terminal construction according to the instant invention also includes a retainer member generally referred to by numeral 34 as best shown in perspective in FIG. 7. Retainer 39 includes a bent retainer tab or tang portion 32 and a weld projection 38, as clearly seen in FIG. 3a, which shows the relation of the parts prior to final assembl. It is to be understood that although a single weld projection 38 has been illustrated, that two or more spaced Weld projections may be provided, if desired. Referring now to FIG. 2, retainer element 36 also includes a pair of sloping spaced wedging surfaces 34 and 36, which are adapted to mate with sloping surfaces 29 and 22 provided by base member til. As will be described in greater detail below, at least a portion of each of sloping surfaces 34 and 36 is adapted to engage with sloping surfaces 20 and 22 when the parts are in fixed, final assembled relation to limit relative movement therebetween in at least one direction.

The terminal, retainer element, and base member are assembled by a unique clamp-weld technique to be described in greater detail below. The L-shaped terminal is inserted into the slot 12 in base it}, as shown in FIG. 3a, with a portion of leg 26 engaging interior surface 35 of base member 1'3. Thereafter, retainer member 39 is inserted into cavity 14 with the retainer tang or tab 32 in retaining well 15, and is oriented so that the outwardly projectin edge 37 of tang 32 is in biting, wedging engagement with wall 18 of cavity 14. The retainer member when so oriented, also places weld projection in engagement with leg of the L-shaped terminal. After the parts have initially been assembled in the manner described above, a clamping force is applied to leg 2-6 of. the L-shapcd terminal and to retainer 30 in the direction of the arrows designated A, as best seen in FIGS. 2, 3 and 3a. This clamping force tends to flatten leg 26 against surface 35 from the position shown in FIG. 3a to that shown in MG. 3. The flattening of leg 26 and the forcing thereof into mating engagement with the surface of the base material, generates a springtype holding force on the underside against the base member. The clamping force in the direction A also tends to urge surfaces 34 and 35 of the retaining member 35), or at least portions thereof, into biting engagement or wedging engagement with bearing sloping surfaces and 22 of base member 1% The clamping force thus tends to squeeze the base material between the leg 26 and the retainer tab to achieve a tight and firm connection therebetween after finai securement of parts as by welding. Merely by way of example and not limitation, it has been found that a force of fifty pounds is suitable as a typical clamping force for terminals of average thickness.

After the parts have been clamped together in the manner described above, and preferably during the clamping step, the parts are welded under pressure, as, for example, by a resistance welding technique. Welding under pressure preferably takes place exteriorly of the base member it} and at a location which is preferably eccentric to the welding projection '33, as shown by the arrows indicated at B. Upon initiation of the resistance welding step or the welding under pressure step, the retainer 3d will tend to pivot relative to leg 24 of the L- shaped terminal and about welding projection 38 as a fulcrum. This pivoting urges projecting portion 37 and tang 32 into biting engagement with wall 13 of cavity 14, and also tends to flatten the tang 32 somewhat thereby creating a resilient holding or bearing pressure to insure tightness of fit. Thus upon welding, retainer element 30 is welded to leg 24 of the L-shaped terminal and in cooperation with the clamping force, leg 26 is fixed in its flattened position against surface 35 and surfaces or portions of surfaces 34 and 36 are in firm, wedging engagement with surfaces 26- and 2 2 of base member ill. Further, due to the pivoting action of retainer member 39 that takes place during weldin retainer tab or tang 3-2 and portion 37 bite into Wedging engagement with wall 18 of cavity 14.. Thus it can be seen that the welding projection 38 serves the dual function of facilitating welding of the retainer 3'9 to the leg 24 of the Lssha-ped terminal and also provides a fulcrum point for the retainer 3%) to rotate about and urge retainer tab or tang 32 into wedging and biting engagement with wall 13 of cavity 14.

The above-described terminal construction and assembly procedure advantageously and uniquely affords an arrangement whereby the terminal is firmly, tightly and securely fastened to a base member, and fracturing or cracking of the base member 16, whether formed of a frangible or resilient material, are advantageously obviated. It can be seen that relative movement between the terminal and the base member in every direction is advantageously obviated, and a tight fit between the parts is assured. \For example, referring to FIG. 2, relative motion of the parts in the direction of the arrows indicated at C is advantageously prevented by the wedging action presented by the mating surfaces 34, 2G and 36, 22 or portions thereof, respectively provided by retainer member 30 and base member 10, and also by interengagement of leg 26 of the L-shaped terminal with the surface 35 of base it).

Referring now to FIG. 3, relative motion between the parts in the direction of the arrows indicated at B is effectively obviated by the instant invention through co-operation of tang portion 3-2 with wall 18 of cavity 14- and by engagement of leg 24 of the L-shaped terminal with the adjacent side wall portions of slot 12. Relative motion between the parts longitudinally of the terminal member in the direction of the clamping force designated by arrows indicated at A, is advantageously precluded by the holding force which is generated by leg 26 in engagement with mating surface 35 in one direction and by the wedging action provided by tang portion 32 (through edge 37 in engagement with wall 18 of cavity 14, and also by co-operation of the respective mating surfaces 34', 2t) and 3 6, 22.

From the above, it can be seen that the terminal constnlction and methods described above advantageously provide a terminal construction in which the tightness of fit between the terminals and base member is assured even during operation at elevated temperatures.

In the embodiment as shown in FIGS. 1-7, an elec trical lead would ordinarily be electrically connected as by welding, soldering, brazing or the like to leg 24% of the L-shaped terminal. It is to be understood that the instant invention is not limited to the particular con struction thus far illustrated and described. For example, the retainer member 36 may take various forms without departing from the spirit and scope of the instant invention. An example of another such embodiment is illustrated in FIGS. 8 and 9, and is generally referred to by numeral 3%.

The retainer member '36) is similar to retainer member 30 described above, but is somewhat greater in dimension and includes a projecting portion 45 which is provided with ear 46 for attaching an electrical lead or conductor thereto. Further, retainer 34) includes two weld projections 38' which are referably aligned so as to provide a fulcrum for purposes described above. Retainer 3i)" includes sloping surface portions 34' and 36" and a bentover tang or offset tab portion 32, which may be identical with and correspond respectively to sloping surfaces 34, 36 and tang 32 of retainer 3d. Retainer 36'', when employed with the L-shaped terminal, permits use of an L-shaped terminal having a leg 24 (as shown in dashe lines in FIG. 9) which is considerably shorter than leg 24 required for retainer 30 since an electrical conductor is b secured directly to the retainer 3% rather than to the terminal leg.

It is to be understood that the word terminal as employed variously throughout the specification and claims, is intended to include any current conducting prong, terminals per se, contact structures, or combination terminals and contacts.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

Dimensions of certain of the parts as shown in the drawings have been modified for the purposes of clarity of illustration.

As many changes could be made in the above constructions and methods without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings, shall be interpreted as illustrative and not in a limiting sense, and it is also intended that the appended claims shall cover all such equivalent variations as come within the true spirit and scope of the invention.

What is claimed is:

1. In combination: a base member; said base member being provided with an open-ended slot; said base member providing a cavity in one surface thereof; said cavity communicating with said slot; said cavity including a retaining well portion and being defined, at least in part, by a first Wall; said cavity including a pair of spaced sloping wedge surfaces extending upwardly and away from each other from opposed sides of said retaining well portion; a terminal member having a first portion thereof disposed in said slot; said terminal member having a second portion thereof in engagement with a surface of said base member when said first portion is disposed in said slot; said first and second portions of said terminal member being integral and forming an acute angle therebetween prior to securement thereof to said base member; a retaining member disposed in said cavity; said retaining member having one portion thereof secured to said first portion of said terminal as by welding; said retaining member including an offset tab portion in wedging engagement with said first wall; said second portion of said terminal member, when said first portion is secured to said retaining member, being urged into firm engagement with said surface of said base member and forming an angle with said first portion of said terminal greater than said acute angle; and said retaining member providing a pair of sloping surfaces complementary to and for engagement with said sloping surfaces provided by said cavity.

2. The combination as set forth in claim 1 and wherein said one portion of said retaining member includes a weld projection.

3. The combination as set forth in claim 1 and wherein said last-named angle is substantially 4. In combination: a base member; said base member being provided with an open-ended slot; said base member providing a cavity in one surface thereof; said cavity communicating with said slot and providing a retaining well portion; said cavity including a wall remote from said slot and defining at least a part of said retaining well portion; said cavity including a pair of spaced sloping wedge surfaces extending upwardly and away from each other and from opposed sides of said retaining well portion; an L-shaped electrical terminal member having one leg thereof disposed in said slot and the other leg thereof in engagement with a surface of said base member remote from said one surface thereof; said legs of said L-shaped terminal member forming an acute angle therebetween prior to securement thereof to said base member; a retaining member disposed in said cavity and having an offset tab portion thereof disposed in said retaining well; said tab portion being olfset in a direction toward said wall; said retaining member having a portion thereof secured to said one leg of said terminal as by welding; said offset tab portion upon welding of said retaining member to said one leg of said terminal,

eing forced into wedging engagement with said wall; said retaining member further including a pair of sloping wedging surfaces complementary to and engageable with said sloping wcdging surfaces provided by said base member in said cavity when in final assembled relation; said other leg of said terminal member, when the latter is secured to said retaining member, being urged into firm engagement with said remote surface of said base member and forming an angle with said one leg of said terminal greater than said acute angle.

5. The combination as set forth in claim 4 and wherein said last-named angle is substantially 90.

6. The combination as set forth in claim 4 and wherein said base member comprises a portion of an electrical switch housing and is formed of a frangible electrically insulating material.

7. The method comprising the steps of providing a base member formed of an electrically insulating materail; forming an open-ended slot therein and a cavity in one surface thereof, with the cavity communicating with said slot; providing a retaining well portion in said cavity which includes at least one wall defining at least a part of said well portion and a pair of spaced sloping wedging surfaces extending upwardly and away from each other from opposed sides of said retaining well portion; providing an electrical terminal having angularly disposed first and second portions; mounting said terminal in said base member with said first portion disposed in said slot and said second portion in engagement with a surface of said base member spaced from said one surface thereof; disposing a retaining member in said retaining wcll portion of said cavity with a portion of said member in engagement with said first portion of said terminal and another portion thereof in engagement with said wall; applying a clamping force between said retaining member and said second portion of said terminal and welding said first-named portion of said retaining member to said first portion of said terminal; said retaining member having sloping surfaces complementary to and engageable with said sloping surfaces provided by said cavity at least portions of said retaining member sloping surfaces being urged into mating engagement with the sloping surfaces provided by said cavity upon the application of said clamping force.

8. The method as set forth in claim 7 and wherein said first-named portion of said retaining member is resistance welded to said first portion of said terminal dur ing said clamping step.

9. The method as set forth in claim 7 and wherein said base member is formed of a frangible material.

it). The method comprising the steps of providing a base member formed of an electrically insulating material; forming an open-ended slot therein and a cavity in one surface thereof, with the cavity communicating with said slot; providing a retaining well portion in said cavity, said well portion being defined at least in part by a wall; providing an electrical terminal havin angularly disposed first and second portions; said first and second potions initially forming an acute angle therebetween prior to mounting thereof in said base; mounting said terminal in said base member with said first portion disposed in said slot and said second portion in engagement with a surface of said base member remote from said one surface thereof; providing a retaining member having a weld projection and an offset tab portion; disposing said retaining member in said cavity with said weld projection engaging said first portion of said terminal and with said offset tab portion engaging said wall; applying a clamping force to said retaining member and said second portion of said terminal whereby to urge said second portion into engagement with said remote surface and to change the angle between said first and second portions of said terminal to one greater than said acute angle; welding said retaining member to said first p rtion of said terminal in the region of said weld projection and applying a force to said retaining member and first portion adjacent said weld projection to pivot said retaining member about said weld projection as a fulcrum point and urge said offset tab portion into wedging engagement with said wall.

11. The method as set forth in claim 10 and wherein the steps of welding and applying a force to said retainer and first section of said terminal member are carried out during the application of said clamping force.

12. The method as set forth in claim 10 and wherein said last-named angle is substantially 13. The method comprising the steps of providing a base member formed of electrically insulating material; forming an open-ended slot therein and a cavity in one surface thereof communicating with said slot; providing a retaining well portion in said cavity, said well portion being defined at least in part by a wall; providing a pair of spaced sloping wedgin surfaces extending upwardly and avay from each other from opposed sides of said retai ing well portion; providing a substantially L-shaped electrical terminal having angularly disposed first and second leg portions; said first and second portions initially forming an acute angle therebetwcen prior to mounting thereof in said base; mounting said terminal in said base member with said first portion disposed in said slot and said second portion in engagement with a surface of said base member remote from said one surface thereof; providing a retaining member having a weld projection and an offset tab portion and a pair of spaced upwardly extending wedge surfaces complementary in shape to said wedge surfaces provided in said base member; disposing said retaining member in said cavity with said well pr0 jection engaging said first section of said terminal, said offset tab portion engaging said wall and with said rctaining member sloping surfaces adjacent said base member sloping surfaces; applying a clamping force to said retaining member and said second portion of said terrni nal whereby to urge said second member into engagement with said remote surface and to change said acute angle between said first and second portions of said terminal to substantially a right angle and also to urge at least portions of said retaining member sloping surfaces into mating engagement with corresponding portions of said base member sloping surfaces; welding said retaining member to said first portion of said terminal in the region of said weld projection and applying a force to said retaining member and first leg portion adjacent said weld projection to pivot said retaining member about said weld projection as a fulcrum and urge said offset tab portion into wedging engagement with said wall.

14. The method as set forth in claim 9 and wherein said base member is formed of a frangible material.

15. In combination: a base member; said base member being provided with an open-ended slot; said base member providing a cavity in one surface thereof; said cavity communicating with said slot; said cavity including a retaining wel portion and being defined, at least in part, by a first wall; a member having a first portion thereof disposed in said slot; said member having a second portion thereof in engagement with a surface of said base member when said first portion is disposed in said slot; said first and second portions of said member being interconnected and forming an acute angle therebetween prior to securement thereof to said base member; a retaining member disposed in said cavity; said retaining member having one portion thereof secured to said first portion of said member as by welding; said retaining member including an offset tab portion in wedging engagement with said first wall; said second portion of said member being urged into firm engagement with said surface of said base member and forming an angle with said first portion of said member greater than said acute angle, when said first portion is secured to said retaining member.

16. in combination: a base member; said base member being provided with an open-ended slot; said base (member providing a cavity in one surface thereof; said cavity communicating with said slot; said cavity including a retaining well portion and being defined, at least in part, by a first well; said cavity including a pair of spaced sloping wedge surfaces extending upwardly and away from each other from opposed sides of said retaining Well portion; a terminal member having a first portion thereof disposed in said slot; said terminal member having a second portion thereof in engagement with a surface of said base member when said first portion is disposed in said slot; said first and second portions of said terminal member being interconnected; a retaining me mber disposed in said cavity; said retaining member having one portion thereof secured to said first portion of said terminal as by welding; said retaining member including an offset tab portion in Wedging engagement with said first wall; said second portion of said terminal member being urged into firm engagement with said surface of said base member, when said first portion is secured to said retaining member; and said retaining member providing a pair of sloping surfaces complementary to and for engagement with said sloping surfaces provided by said cavity.

17. In combination: a base member, said base member having an open-ended slot, and a cavity in one surface thereof, said cavity communicating with said slot and including a retaining well portion, said retaining well portion being defined at least in part by a first wall; an electrically conductive terminal member having a first portion ereof disposed in said slot; said terminal member having a second portion angularly disposed to said first portion and disposed in engagement with a surface of said base member when said first portion is disposed in said slot; a retaining member disposed in said cavity, said retaining member having one portion thereof provided with a weld projection, said one portion of said retaining member being welded to said first portion of said terminal member, said retaining member further including an offset tab portion maintained in resilient Wedging engagement with said first wall when said one portion of said retaining member is welded to said first portion of said terminal member, said retaining member pivoting about said weld projection as a fulcrum point and urging said offset tab portion into wedging engagement with said first Wall of said cavity when said one portion of said retaining mem- 10 her is welded to said first portion of said terminal memher; and said second portion of said terminal member also being urged into firm engagement with said surface of said base member when said first portion of the terminal member is Welded to said one portion of said retainin g member.

18. in combination: a base member having an openended slot and a retaining well communicating with said slot, said retaining well having a Wall, said wall also defining at least a part of said slot; a terminal member having a first portion thereof disposed in said slot; a retaining member including a first portion interconnected with and extending at an angle to an offset tab portion, said first portion being provided With a weld projection; said retaining member being disposed in said retaining well with said first portion welded to said first terminal portion and said offset tab portion in Wedging engagement with said Wall, said retaining member pivoting to urge said offset tab portion into wedging engagement with said Wall when said first retaining member portion is Welded to said first terminal member portion.

19. The combination set forth in claim 18 and wherein said terminal member includes a second portion disposed in engagement with a surface of said base member; said first and second terminal portions being interconnected and forming an acute angle therebetween prior to Welding of said first terminal portion to said first portion of said retaining member, said second terminal portion being urged into firm engagement with said base member surface and forming an angle with said first terminal portion greater than said acute angle, when said first terminal portion is welded to said first portion of said retaining member.

References Cited in the file of this patent UNITED STATES PATENTS 1,747,896 Gates Feb. 18, 1930 2,205,146 Larkin June 18, 1940 2,425,670 Buell Aug. 12, 1947 2,507,780 Gilbert May 16, 1950 2,691,147 Sutton et a1. Oct. 5, 1954 2,762,026 Knohl Sept. 4, 1956 2,912,670 Flanagan et al. Nov. 10, 1959 2,923,911 Demurjian Feb. 2, 1960 2,981,673 Johnson Apr. 25, 1961 FOREIGN PATENTS 1,082,646 Germany June 2, 1960 157,103 Sweden Dec. 4, 1956 

18. IN COMBINATION: A BASE MEMBER HAVING AN OPENENDED SLOT AND A RETAINING WELL COMMUNICATING WITH SAID SLOT, SAID RETAINING WELL HAVING A WALL, SAID WALL ALSO DEFINING AT LEAST A PART OF SAID SLOT; A TERMINAL MEMBER HAVING A FIRST PORTION THEREOF DISPOSED IN SAID SLOT; A RETAINING MEMBER INCLUDING A FIRST PORTION INTERCONNECTED WITH AND EXTENDING AT AN ANGLE TO AN OFFSET TAB PORTION, SAID FIRST PORTION BEING PROVIDED WITH A WELD PROJECTION; SAID RE- 